Mixed source localization and gain-phase perturbation calibration in partly calibrated symmetric uniform linear arrays

A novel technique for localization of narrowband near-field sources is presented. The technique utilizes the sensor-angle distribution (SAD) that treats the source range and direction-of-arrival (DOA) information as sensor-dependent phase progression. The SAD draws parallel to quadratic time-frequency distributions and, as such, is able to reveal the changes in the spatial frequency over sensor positions. For a moderate source range, the SAD signature is of a polynomial shape, thus simplifying the parameter estimation. Both uniform and sparse linear arrays are considered in this work. To exploit the sparsity and continuity of the SAD signature in the joint space and spatial frequency domain, a modified Bayesian compressive sensing algorithm is exploited to estimate the SAD signature. In this method, a spike-and-slab prior is used to statistically encourage sparsity of the SAD across each segmented SAD region, and a patterned prior is imposed to enforce the continuous structure of the SAD. The results are then mapped back to source range and DOA estimation for source localization. The effectiveness of the proposed technique is verified using simulation results with uniform and sparse linear arrays where the array sensors are located on a grid but with consecutive and missing positions.

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Distributed 3D Source Localization from 2D DOA Measurements Using Multiple Linear Arrays

Wireless Communications and Mobile Computing ◽

10.1155/2017/1049141 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Antonio Canclini ◽

Fabio Antonacci ◽

Augusto Sarti ◽

Stefano Tubaro

Keyword(s):

Source Localization ◽

Microphone Array ◽

Source Location ◽

Location Estimation ◽

Planar Geometry ◽

Linear Arrays ◽

Multiple Sensors ◽

3D Space ◽

Acoustic Sensor Networks ◽

Traditional Approaches

This manuscript addresses the problem of 3D source localization from direction of arrivals (DOAs) in wireless acoustic sensor networks. In this context, multiple sensors measure the DOA of the source, and a central node combines the measurements to yield the source location estimate. Traditional approaches require 3D DOA measurements; that is, each sensor estimates the azimuth and elevation of the source by means of a microphone array, typically in a planar or spherical configuration. The proposed methodology aims at reducing the hardware and computational costs by combining measurements related to 2D DOAs estimated from linear arrays arbitrarily displaced in the 3D space. Each sensor measures the DOA in the plane containing the array and the source. Measurements are then translated into an equivalent planar geometry, in which a set of coplanar equivalent arrays observe the source preserving the original DOAs. This formulation is exploited to define a cost function, whose minimization leads to the source location estimation. An extensive simulation campaign validates the proposed approach and compares its accuracy with state-of-the-art methodologies.

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TWO UNIFORM LINEAR ARRAYS FOR NON-COHERENT AND COHERENT SOURCES FOR TWO DIMENSIONAL SOURCE LOCALIZATION

Progress In Electromagnetics Research Letters ◽

10.2528/pierl14051903 ◽

2014 ◽

Vol 47 ◽

pp. 31-39 ◽

Cited By ~ 1

Author(s):

Muhammad Omer ◽

Nizar Tayem ◽

Ahmed Abul Hussain

Keyword(s):

Source Localization ◽

Two Dimensional ◽

Linear Arrays ◽

Coherent Sources

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Linear Arrays of Helical Polyribosomes in Cells Exposed to Antitumor Drug Vincristine Sulfate

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063706 ◽

1969 ◽

Vol 27 ◽

pp. 358-359

Author(s):

Awtar Krishan

Keyword(s):

Close Association ◽

Annulate Lamellae ◽

Large Array ◽

Vincristine Sulfate ◽

Linear Arrays ◽

Golgi Membranes ◽

Related Drug ◽

Drug Leads ◽

Lethal Doses ◽

Vinblastine Sulfate

Earle's L-929 fibroblasts treated with mitosis-arresting but sub-lethal doses of vinblastine sulfate (VLB) show hypertrophy of the granular endoplasmic reticulum and annulate lamellae. Exposure of the cells to heavier doses of vincristine sulfate (VCR), a VLB-related drug, leads to the accumulation of large amounts of helical polyribosomes, Golgi membranes and crystals in the cytoplasm. In many of these cells a large number of helical polyribosomes are arranged in prominent linear rows, some of which may be up to 5 micrometers in length. Figure 1 shows a large array of helical polyribosomes near a crystalline mass (CRS) in an Earle's L-929 fibroblast exposed to VCR (5ϒ/ml.) for 3 hours At a higher magnification, as seen in figure 2, the helical polyribosomes are seen arranged in parallel rows. In favorably cut sections, a prominent backbone like "stalk" of finely granular material, measuring approximately 300Å in width is seen in close association with the linear rows of helical polyribosomes.

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